The present invention relates to a honeycomb panel fixing device for fixing a honeycomb panel, which is used as an interior material of a manned spacecraft, to a framework and the like.
As an interior material of a manned spacecraft, a light, strong honeycomb panel is employed. If the honeycomb panel is fixed to a structure such as a framework, using a fixing bolt through the honeycomb panel in order to design the interior of the spacecraft, there occurs a drawback in which the honeycomb panel will be crushed by pressure of a head portion of the fixing bolt.
A prior art fixing device for fixing a honeycomb panel to a structure such as a framework, is disclosed in U.S. Pat. Nos. 5,378,099, 5,240,543, 5,093,957, 5,082,405, 5,013,613, 4,941,785, 4,800,643, 4,729,705, 4,717,612, and 5,480,729.
Another prior art fixing device is shown in FIG. 7 as a structure for fixing a honeycomb panel. Referring to FIG. 7, a through-hole 2 is formed through a honeycomb panel 1 in its thickness direction, and a bushing 3 is inserted into the through-hole 2. The bushing 3 is constituted of synthetic resin and shaped like a cylinder with a bottom. A bolt hole 4 is formed in the bottom of the bushing 3 and a flange section 5 is provided at the opening thereof.
In order to design the interior by fixing the honeycomb panel 1 to a structure 6 such as a framework, an adhesive 7 or a potting material is applied to the inner surface of the through-hole 2, and then the bushing 3 is inserted into the through-hole 2 and fixed adhesively to the honeycomb panel 1. If a fixing bolt 8 is screwed into a screw hole 9 of the structure 6, the flange section 5 of the bushing 3 is bonded to the honeycomb panel 1, and the honeycomb panel 1 is fixed to the structure 6 by means of the bushing 3.
However, the honeycomb panel 1 has an error in thickness when it is formed, though the bushing 3 is formed without any error in dimension. If the honeycomb panel 1 is thin and its level is lower than the height of the bushing 3, a gap g will be created between the back of the honeycomb panel 1 and the structure 6 as shown in FIG. 8, and the honeycomb panel 1 cannot be fixed firmly to the structure 6.
On the other hand, if the honeycomb panel 1 is thick and its level is higher than the height of the bushing 3, as shown in FIG. 9, there will occur a problem in which a gap g will be created between the bottom of the bushing 3 and the structure 6, and the flange section 5 is strongly pressed on the edge of the opening of the through-hole 2 by tightening the fixing bolt 8, thereby deforming the honeycomb panel 1.
If, furthermore, the flange section 5 is removed from the bushing 3, as shown in FIG. 10, in order to eliminate an error in dimension of the honeycomb panel 1, there will occur a problem in which the honeycomb panel 1 is separated from the structure 6 and floated under conditions of weightlessness, as indicated by a two-dot-one-dash line, without loosening the fixing bolt 8, if the adhesive 7 lacks its adhesive strength.